Method for forming ultra low k films using electron beam

ABSTRACT

The present invention generally provides a method for depositing a low dielectric constant film using an e-beam treatment. In one aspect, the method includes delivering a gas mixture comprising one or more organosilicon compounds and one or more hydrocarbon compounds having at least one cyclic group to a substrate surface at deposition conditions sufficient to deposit a non-cured film comprising the at least one cyclic group on the substrate surface. The method further includes substantially removing the at least one cyclic group from the non-cured film using an electron beam at curing conditions sufficient to provide a dielectric constant less than 2.5 and a hardness greater than 0.5 GPa.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to the fabrication of integratedcircuits. More particularly, the invention relates to a method fordepositing dielectric layers on a substrate and the structures formed bythe dielectric layer.

[0003] 2. Description of the Related Art

[0004] Semiconductor device geometries have dramatically decreased insize since such devices were first introduced several decades ago. Sincethen, integrated circuits have generally followed the two year/half-sizerule (often called Moore's Law), which means that the number of devicesthat will fit on a chip doubles every two years. Today's fabricationplants are routinely producing devices having 0.13 μm and even 0.1 μmfeature sizes, and tomorrow's plants soon will be producing deviceshaving even smaller geometries.

[0005] In order to further reduce the size of devices on integratedcircuits, it has become necessary to use conductive materials having lowresistivity and to use insulators having low dielectric constants toreduce the capacitive coupling between adjacent metal lines. One suchlow k material is spin-on glass, such as un-doped silicon glass (USG) orfluorine-doped silicon glass (FSG), which can be deposited as a gap filllayer in a semiconductor manufacturing process. Other examples of low kmaterials include carbon doped silicon dioxide andpolytetrafluoroethylene. However, the continued reduction in devicegeometries has generated a demand for films having even lower k values.

[0006] Recent developments in low dielectric constants have focused onincorporating silicon, carbon, and oxygen atoms into the deposited film.One challenge in this area has been to develop a Si, C, and O containingfilm that has a low k value, but also exhibits desirable thermal andmechanical properties. Most often, films made of a Si, C, and O networkthat have a desirable dielectric constant exhibit poor mechanicalstrength and are easily damaged by etch chemistry and subsequent plasmaexposure, causing failure of the integrated circuit.

[0007] Therefore, there is a need for a process for making lowdielectric constant materials that would improve the speed andefficiency of devices on integrated circuits as well as the durabilityand mechanical integrity of the integrated circuit.

SUMMARY OF THE INVENTION

[0008] The present invention generally provides a method for depositinga low dielectric constant film. In one aspect, the method includesdelivering a gas mixture comprising one or more organosilicon compoundsand one or more hydrocarbon compounds having at least one cyclic groupto a substrate surface at deposition conditions sufficient to deposit anon-cured film comprising the at least one cyclic group on the substratesurface and having a hardness less than about 0.3 GPa. The methodfurther includes substantially removing the at least one cyclic groupfrom the non-cured film using an electron beam at curing conditionssufficient to provide a dielectric constant less than 2.5 and a hardnessgreater than 0.5 GPa.

[0009] In another aspect, the method includes delivering a gas mixturecomprising one or more organosilicon compounds, one or more hydrocarboncompounds having at least one cyclic group, and two or more oxidizinggases to a substrate surface at deposition conditions sufficient todeposit a non-cured film comprising the at least one cyclic group on thesubstrate surface and having a hardness less than 0.3 GPa, andsubstantially removing the at least one cyclic group from the non-curedfilm using an electron beam at curing conditions sufficient to provide adielectric constant less than 2.2 and a hardness greater than 0.4 GPa.

[0010] In yet another aspect, the method includes delivering a gasmixture comprising two or more organosilicon compounds, one or morehydrocarbon compounds having at least one cyclic group, and one or moreoxidizing gases to a substrate surface at deposition conditionssufficient to deposit a non-cured film comprising the at least onecyclic group on the substrate surface, and substantially removing the atleast one cyclic group from the non-cured film using an electron beam atcuring conditions sufficient to provide a dielectric constant less than2.5 and a hardness greater than 0.5 GPa, wherein the electron beam has adosage greater than about 200 micro coulombs per cm².

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] So that the manner in which the above recited features of thepresent invention can be understood in detail, a more particulardescription of the invention, briefly summarized above, may be had byreference to embodiments, some of which are illustrated in the appendeddrawings. It is to be noted, however, that the appended drawingsillustrate only typical embodiments of this invention and are thereforenot to be considered limiting of its scope, for the invention may admitto other equally effective embodiments.

[0012]FIG. 1 is a cross-sectional diagram of an exemplary CVD reactorconfigured for use according to embodiments described herein.

[0013]FIG. 2 is a flow chart of a hierarchical control structure of acomputer program useful in conjunction with the exemplary CVD reactor ofFIG. 1.

[0014]FIG. 3 is a cross sectional view showing a damascene structurecomprising a low dielectric constant film as described herein.

[0015] FIGS. 4A-4C are cross sectional views showing one embodiment of adamascene deposition sequence.

[0016]FIG. 5 is a cross sectional view showing a dual damascenestructure comprising two low dielectric constant films as describedherein.

[0017] FIGS. 6A-6E are cross sectional views showing one embodiment of adual damascene deposition sequence.

[0018]FIG. 7 shows an exemplary integrated processing platform.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0019] The present invention includes a significant and unexpectedreduction in dielectric constants for films comprising silicon, oxygen,and carbon by blending one or more compounds having at least one cyclicgroup, one or more organosilicon compounds, and optionally an oxidizinggas at conditions sufficient to form a pre-treated film network. In oneaspect, one or more organic compounds having at least one cyclic groupand one or more organosilicon compounds are reacted with an oxidizinggas in amounts sufficient to deposit a low dielectric constant film on asemiconductor substrate.

[0020] The film may be deposited using plasma assistance within aprocessing chamber capable of performing chemical vapor deposition(CVD). The plasma may be generated using pulse RF, high frequency RF,dual frequency, dual phase RF, or any other known or yet to bediscovered plasma generation technique. Following deposition of thefilm, the film is cured by electron beam to remove pendant organicgroups, such as cyclic groups of the organic compounds that have beenincorporated into the film network during deposition.

[0021] The curing step supplies energy to the film network to volatizeand remove at least a portion of the cyclic groups in the film network,leaving behind a more porous film network having a lower dielectricconstant. In most cases, the cured film demonstrates a hardness at leasttwo times, and as much as 600%, more than a non-cured film depositedaccording to embodiments described herein. Films cured using e-beam showan unexpected reduction in k value and an unexpected increase inhardness, not achievable with conventional curing techniques. Typically,the cured film has a dielectric constant of about 2.5 or less,preferably about 2.2 or less, and a hardness greater than about 0.6 GPa.

[0022] The term “organosilicon compound” as used herein is intended torefer to compounds containing carbon atoms in organic groups, and can becyclic or linear. Organic groups may include alkyl, alkenyl,cyclohexenyl, and aryl (what others) groups in addition to functionalderivatives thereof. Preferably, the organosilicon compounds includesone or more carbon atoms attached to a silicon atom whereby the carbonatoms are not readily removed by oxidation at suitable processingconditions. The organosilicon compounds may also preferably include oneor more oxygen atoms. In one aspect, a preferred organosilicon compoundhas an oxygen to silicon atom ratio of at least 1:1, and more preferablyat least 2:1, such as about 4:1.

[0023] Suitable cyclic organosilicon compounds include a ring structurehaving three or more silicon atoms, and optionally one or more oxygenatoms. Commercially available cyclic organosilicon compounds includerings having alternating silicon and oxygen atoms with one or two alkylgroups bonded to the silicon atoms. Some exemplary cyclic organosiliconcompounds include: 1,3,5-trisilano-2,4,6-trimethylene, SiH₂CH₂₃ (cyclic) 2,4,6,8-tetramethylcyclotetrasiloxane (TMCTS) SiHCH₃—O₄ (cyclic) octamethylcyclotetrasiloxane (OMCTS), Si(CH₃)₂—O₄  (cyclic)2,4,6,8,10-pentamethylcyclopentasiloxane, SiHCH₃—O₅  (cyclic)1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, SiH₂—CH₂—SiH₂—O₂ (cyclic) hexamethylcyclotrisiloxane Si(CH₃)₂—O₃  (cyclic)

[0024] Suitable linear organosilicon compounds include aliphaticorganosilicon compounds having linear or branched structures with one ormore silicon atoms and one or more carbon atoms. The organosiliconcompounds may further include one or more oxygen atoms. Some exemplarylinear organosilicon compounds include: methylsilane, CH₃—SiH₃dimethylsilane, (CH₃)₂—SiH₂ trimethylsilane, (CH₃)₃—SiH ethylsilane,CH₃—CH₂—SiH₃ disilanomethane, SiH₃—CH₂—SiH₃ bis(methylsilano)methane,CH₃—SiH₂—CH₂—SiH₂—CH₃ 1,2-disilanoethane, SiH₃—CH₂—CH₂—SiH₃1,2-bis(methylsilano)ethane, CH₃—SiH₂—CH₂—CH₂—SiH₂—CH₃2,2-disilanopropane, SiH₃—C(CH₃)₂—SiH₃ diethoxymethylsilane (DEMS),CH₃—Si^(H)—(O—CH₂—CH₃)₂ 1,3-dimethyldisiloxane, CH₃—SiH₂—O—SiH₂—CH₃1,1,3,3-tetramethyldisiloxane, (CH₃)₂—SiH—O—SiH—(CH₃)₂hexamethyldisiloxane (HMDS), (CH₃)₃—Si—O—Si—(CH₃)₃1,3-bis(silanomethylene)disiloxane, (SiH₃—CH₂—SiH₂₂Obis(1-methyldisiloxanyl)methane, (CH₃—SiH₂—O—SiH₂₂CH₂2,2-bis(1-methyldisiloxanyl)propane, (CH₃—SiH₂—O—SiH₂₂C(CH₃)₂hexamethoxydisiloxane (HMDOS) (CH₃O)₃—Si—O—Si—(OCH₃)₃dimethyldimethoxysilane (DMDMOS) (CH₃O)₂—Si—(CH₃)₂dimethoxymethylvinylsilane (DMMVS) (CH₃O)₂—Si—(CH₃)—CH₂═CH₃

[0025] The term “cyclic group” as used herein is intended to refer to aring structure. The ring structure may contain as few as three atoms.The atoms may include carbon, silicon, nitrogen, oxygen, fluorine, andcombinations thereof, for example. The cyclic group may include one ormore single bonds, double bonds, triple bonds, and any combinationthereof. For example, a cyclic group may include one or more aromatics,aryls, phenyls, cyclohexanes, cyclohexadienes, cycloheptadienes, andcombinations thereof. The cyclic group may also be bi-cyclic ortri-cyclic. Further, the cyclic group is preferably bonded to a linearor branched functional group. The linear or branched functional grouppreferably contains an alkyl or vinyl alkyl group and has between oneand twenty carbon atoms. The linear or branched functional group mayalso include oxygen atoms, such as a ketone, ether, and ester. Someexemplary compounds having at least one cyclic group includealpha-terpinene (ATP), vinylcyclohexane (VCH), and phenylacetate, justto name a few.

[0026] Suitable oxidizing gasses include oxygen (O₂), ozone (O₃),nitrous oxide (N₂O), carbon monoxide (CO), carbon dioxide (CO₂), water(H₂O), 2,3-butane dione or combinations thereof. When ozone is used asan oxidizing gas, an ozone generator converts from 6% to 20%, typicallyabout 15%, by weight of the oxygen in a source gas to ozone, with theremainder typically being oxygen. However, the ozone concentration maybe increased or decreased based upon the amount of ozone desired and thetype of ozone generating equipment used. Disassociation of oxygen or theoxygen containing compounds may occur in a microwave chamber prior toentering the deposition chamber to reduce excessive dissociation of thesilicon containing compounds. Preferably, radio frequency (RF) power isapplied to the reaction zone to increase dissociation.

[0027] The e-beam treatment typically has a dose between about 50 andabout 2000 micro coulombs per square centimeter (μc/cm²) at about 1 to20 kiloelectron volts (KeV). The e-beam treatment is typically operatedat a temperature between about room-temperature and about 450° C. forabout 1 minute to about 15 minutes, such as about 2 minutes. Preferably,the e-beam treatment is performed at about 400° C. for about 2 minutes.In one aspect, the e-beam treatment conditions include 4.5 kV, 1.5 mAand 500 μc/cm² at 400 C. Although any e-beam device may be used, oneexemplary device is the EBK chamber, available from Applied Materials,Inc.

[0028] The e-beam curing process improves mechanical strength of thedeposited film network and also lowers the k-value. The energized e-beamalters the chemical bonding in the molecular network of the depositedfilm and removes at least a portion of the molecular groups from thefilm. The removal of the molecular groups creates voids or pores withinthe film, lowering the k value. The e-beam treatment also strengthensthe film network by cross-linking Si—O—Si or Si—C—Si chains as inferredfrom FTIR spectroscopy.

[0029] Preferably, the deposited film has a carbon content between about10 and about 30 atomic percent, such as between about 10 and about 30atomic percent after curing. The carbon content of the deposited filmsrefers to an elemental analysis of the film structure. The carboncontent is represented by the percent of carbon atoms in the depositedfilm, excluding hydrogen atoms, which are difficult to quantify. Forexample, a film having an average of one silicon atom, one oxygen atom,one carbon atom and two hydrogen atoms has a carbon content of 20 atomicpercent (one carbon atom per five total atoms), or a carbon content of33 atomic percent excluding hydrogen atoms (one carbon atom per threetotal atoms).

[0030] During deposition, the substrate is typically maintained at atemperature between about −20° C. and about 450° C. A power densityranging between about 0.03 W/cm² and about 3.2 W/cm², which is a RFpower level of between about 10 W and about 2000 W for a 200 mmsubstrate is typically used. Preferably, the RF power level is betweenabout 300 W and about 1700 W. The RF power is provided at a frequencybetween about 0.01 MHz and 300 MHz. The RF power may be cycled or pulsedto reduce heating of the substrate and promote greater porosity in thedeposited film. The RF power may also be continuous or discontinuous. Anexemplary processing chamber for depositing a low dielectric filmaccording to embodiments described herein is described below.

[0031] Exemplary CVD Reactor

[0032]FIG. 1 shows a vertical, cross-section view of a parallel platechemical vapor deposition processing chamber 10 having a high vacuumregion 15. The processing chamber 10 contains a gas distributionmanifold 11 having perforated holes for dispersing process gasesthere-through to a substrate (not shown). The substrate rests on asubstrate support plate or susceptor 12. The susceptor 12 is mounted ona support stem 13 which connects the susceptor 12 to a lift motor 14.The lift motor 14 raises and lowers the susceptor 12 between aprocessing position and a lower, substrate-loading position so that thesusceptor 12 (and the substrate supported on the upper surface ofsusceptor 12) can be controllably moved between a lowerloading/off-loading position and an upper processing position which isclosely adjacent to the manifold 11. When the susceptor 12 and thesubstrate are in the upper processing position 14, they are surroundedby an insulator 17.

[0033] During processing, gases introduced to the manifold 11 areuniformly distributed radially across the surface of the substrate. Avacuum pump 32 having a throttle valve controls the exhaust rate ofgases from the chamber through a manifold 24. Deposition and carriergases flow through gas lines 18 into a mixing system 19 and then to themanifold 11. Generally, each process gas supply line 18 includes (i)safety shut-off valves (not shown) that can be used to automatically ormanually shut off the flow of process gas into the chamber, and (ii)mass flow controllers (also not shown) to measure the flow of gasthrough the gas supply lines 18. When toxic gases are used in theprocess, several safety shut-off valves are positioned on each gassupply line 18 in conventional configurations.

[0034] The deposition process performed in the processing chamber 10 canbe either a thermal process or a plasma enhanced process. In a plasmaprocess, a controlled plasma is typically formed adjacent the substrateby RF energy applied to the gas distribution manifold 11 using a RFpower supply 25. Alternatively, RF power can be provided to thesusceptor 12 or RF power can be provided to different components atdifferent frequencies. The RF power supply 25 can supply either singleor mixed frequency RF power to enhance the decomposition of reactivespecies introduced into the high vacuum region 15. A mixed frequency RFpower supply typically supplies power at a high RF frequency (RF1) of13.56 MHz to the distribution manifold 11 and at a low RF frequency(RF2) of 360 KHz to the susceptor 12.

[0035] When additional dissociation of the oxidizing gas is desired, anoptional microwave chamber 28 can be used to input from between about 0Watts and about 6000 Watts to the oxidizing gas prior to the gasentering the processing chamber 10. The additional microwave power canavoid excessive dissociation of the organosilicon compounds prior toreaction with the oxidizing gas. A gas distribution plate (not shown)having separate passages for the organosilicon compound and theoxidizing gas is preferred when microwave power is added to theoxidizing gas.

[0036] Typically, any or all of the chamber lining, distributionmanifold 11, susceptor 12, and various other reactor hardware is madeout of material such as aluminum or anodized aluminum. An example ofsuch a CVD reactor is described in commonly assigned U.S. Pat. No.5,000,113, entitled “A Thermal CVD/PECVD Reactor and Use for ThermalChemical Vapor Deposition of Silicon Dioxide and In-situ Multi-stepPlanarized Process”, issued to Wang et al., which is incorporated byreference herein. The processing system 10 may be integrated into anintegrated processing platform, such as a Producer™ platform availablefrom Applied Materials, Inc. Details of the Producer™ platform aredescribed in commonly assigned U.S. Pat. No. 5,855,681, entitled “UltraHigh Throughput Wafer Vacuum Processing System”, issued to Maydan etal., which is incorporated by reference herein.

[0037] A system controller 34 controls the motor 14, the gas mixingsystem 19, and the RF power supply 25 which are connected therewith bycontrol lines 36. The system controller 34 controls the activities ofthe CVD reactor and typically includes a hard disk drive, a floppy diskdrive, and a card rack. The card rack contains a single board computer(SBC), analog and digital input/output boards, interface boards, andstepper motor controller boards. The system controller 34 conforms tothe Versa Modular Europeans (VME) standard which defines board, cardcage, and connector dimensions and types. The VME standard also definesthe bus structure having a 16-bit data bus and 24-bit address bus.

[0038]FIG. 2 is a flow chart of a hierarchical control structure of acomputer program product useful in conjunction with the exemplary CVDreactor of FIG. 1. The system controller 34 operates under the controlof a computer program 410 stored on the hard disk drive 38. The computerprogram dictates the timing, mixture of gases, RF power levels,susceptor position, and other parameters of a particular process. Thecomputer program code can be written in any conventional computerreadable programming language such as, for example, 68000 assemblylanguage, C, C++, or Pascal. Suitable program code is entered into asingle file, or multiple files, using a conventional text editor, andstored or embodied in a computer usable medium, such as a memory systemof the computer. If the entered code text is in a high level language,the code is compiled, and the resultant compiler code is then linkedwith an object code of precompiled windows library routines. To executethe linked compiled object code, the system user invokes the objectcode, causing the computer system to load the code in memory, from whichthe CPU reads and executes the code to perform the tasks identified inthe program.

[0039] Still referring to FIG. 2, a user enters a process set number andprocess chamber number into a process selector subroutine 420 inresponse to menus or screens displayed on the CRT monitor by using thelight pen interface. The process sets are predetermined sets of processparameters necessary to carry out specified processes, and areidentified by predefined set numbers. The process selector subroutine420 (i) selects a desired process chamber on a cluster tool such as anCentura® platform (available from Applied Materials, Inc.), and (ii)selects a desired set of process parameters needed to operate theprocess chamber for performing the desired process. The processparameters for performing a specific process are provided to the user inthe form of a recipe and relate to process conditions such as, forexample, process gas composition, flow rates, temperature, pressure,plasma conditions such as RF bias power levels and magnetic field powerlevels, cooling gas pressure, and chamber wall temperature. Theparameters specified by the recipe are entered utilizing the lightpen/CRT monitor interface. The signals for monitoring the process areprovided by the analog input and digital input boards of the systemcontroller 34 and the signals for controlling the process are output tothe analog output and digital output boards of the system controller 34.

[0040] A process sequencer subroutine 430 comprises program code foraccepting the identified process chamber and set of process parametersfrom the process selector subroutine 420, and for controlling operationof the various process chambers. Multiple users can enter process setnumbers and process chamber numbers, or a user can enter multipleprocess chamber numbers, so the sequencer subroutine 430 operates toschedule the selected processes in the desired sequence. Preferably thesequencer subroutine 430 includes computer readable program code toperform the steps of (i) monitoring the operation of the processchambers to determine if the chambers are being used, (ii) determiningwhat processes are being carried out in the chambers being used, and(iii) executing the desired process based on availability of a processchamber and type of process to be carried out. Conventional methods ofmonitoring the process chambers can be used, such as polling. Whenscheduling a process execute, the sequencer subroutine 430 can bedesigned to take into consideration the present condition of the processchamber being used in comparison with the desired process conditions fora selected process, or the “age” of each particular user enteredrequest, or any other relevant factor a system programmer desires toinclude for determining the scheduling priorities.

[0041] Once the sequencer subroutine 430 determines which processchamber and process set combination is going to be executed next, thesequencer subroutine 430 causes execution of the process set by passingthe particular process set parameters to a chamber manager subroutine440 which controls multiple processing tasks in a process chamberaccording to the process set determined by the sequencer subroutine 430.For example, the chamber manager subroutine 440 includes program codefor controlling CVD process operations in the process chamber 10. Thechamber manager subroutine 440 also controls execution of variouschamber component subroutines which control operation of the chambercomponent necessary to carry out the selected process set. Examples ofchamber component subroutines are susceptor control subroutine 450,process gas control subroutine 460, pressure control subroutine 470,heater control subroutine 480, and plasma control subroutine 490. Thosehaving ordinary skill in the art would readily recognize that otherchamber control subroutines can be included depending on what processesare desired to be performed in a processing chamber.

[0042] In operation, the chamber manager subroutine 440 selectivelyschedules or calls the process component subroutines in accordance withthe particular process set being executed. The chamber managersubroutine 440 schedules the process component subroutines similarly tohow the sequencer subroutine 430 schedules which process chamber andprocess set is to be executed next. Typically, the chamber managersubroutine 440 includes steps of monitoring the various chambercomponents, determining which components needs to be operated based onthe process parameters for the process set to be executed, and causingexecution of a chamber component subroutine responsive to the monitoringand determining steps.

[0043] Operation of particular chamber component subroutines will now bedescribed with reference to FIG. 2. The susceptor control positioningsubroutine 450 comprises program code for controlling chamber componentsthat are used to load the substrate onto the susceptor 12, andoptionally to lift the substrate to a desired height in the processingchamber 10 to control the spacing between the substrate and the gasdistribution manifold 11. When a substrate is loaded into the processingchamber 10, the susceptor 12 is lowered to receive the substrate, andthereafter, the susceptor 12 is raised to the desired height in thechamber to maintain the substrate at a first distance or spacing fromthe gas distribution manifold 11 during the CVD process. In operation,the susceptor control subroutine 450 controls movement of the susceptor12 in response to process set parameters that are transferred from thechamber manager subroutine 440.

[0044] The process gas control subroutine 460 has program code forcontrolling process gas compositions and flow rates. The process gascontrol subroutine 460 controls the open/close position of the safetyshut-off valves, and also ramps up/down the mass flow controllers toobtain the desired gas flow rate. The process gas control subroutine 460is invoked by the chamber manager subroutine 440, as are all chambercomponents subroutines, and receives from the chamber manager subroutineprocess parameters related to the desired gas flow rates. Typically, theprocess gas control subroutine 460 operates by opening the gas supplylines, and repeatedly (i) reading the necessary mass flow controllers,(ii) comparing the readings to the desired flow rates received from thechamber manager subroutine 440, and (iii) adjusting the flow rates ofthe gas supply lines as necessary. Furthermore, the process gas controlsubroutine 460 includes steps for monitoring the gas flow rates forunsafe rates, and activating the safety shut-off valves when an unsafecondition is detected.

[0045] In some processes, an inert gas such as helium or argon is putinto the processing chamber 10 to stabilize the pressure in the chamberbefore reactive process gases are introduced. For these processes, theprocess gas control subroutine 460 is programmed to include steps forflowing the inert gas into the chamber 10 for an amount of timenecessary to stabilize the pressure in the chamber, and then the stepsdescribed above would be carried out. Additionally, when a process gasis to be vaporized from a liquid precursor, the process gas controlsubroutine 460 would be written to include steps for bubbling a deliverygas such as helium through the liquid precursor in a bubbler assembly.For this type of process, the process gas control subroutine 460regulates the flow of the delivery gas, the pressure in the bubbler, andthe bubbler temperature in order to obtain the desired process gas flowrates. As discussed above, the desired process gas flow rates aretransferred to the process gas control subroutine 460 as processparameters. Furthermore, the process gas control subroutine 460 includessteps for obtaining the necessary delivery gas flow rate, bubblerpressure, and bubbler temperature for the desired process gas flow rateby accessing a stored table containing the necessary values for a givenprocess gas flow rate. Once the necessary values are obtained, thedelivery gas flow rate, bubbler pressure and bubbler temperature aremonitored, compared to the necessary values and adjusted accordingly.

[0046] The pressure control subroutine 470 comprises program code forcontrolling the pressure in the processing chamber 10 by regulating thesize of the opening of the throttle valve in the exhaust pump 32. Thesize of the opening of the throttle valve is set to control the chamberpressure to the desired level in relation to the total process gas flow,size of the process chamber, and pumping set point pressure for theexhaust pump 32. When the pressure control subroutine 470 is invoked,the desired, or target pressure level is received as a parameter fromthe chamber manager subroutine 440. The pressure control subroutine 470operates to measure the pressure in the processing chamber 10 by readingone or more conventional pressure manometers connected to the chamber,compare the measure value(s) to the target pressure, obtain PID(proportional, integral, and differential) values from a stored pressuretable corresponding to the target pressure, and adjust the throttlevalve according to the PID values obtained from the pressure table.Alternatively, the pressure control subroutine 470 can be written toopen or close the throttle valve to a particular opening size toregulate the processing chamber 10 to the desired pressure.

[0047] The heater control subroutine 480 comprises program code forcontrolling the temperature of the heat modules or radiated heat that isused to heat the susceptor 12. The heater control subroutine 480 is alsoinvoked by the chamber manager subroutine 440 and receives a target, orset point, temperature parameter. The heater control subroutine 480measures the temperature by measuring voltage output of a thermocouplelocated in a susceptor 12, compares the measured temperature to the setpoint temperature, and increases or decreases current applied to theheat module to obtain the set point temperature. The temperature isobtained from the measured voltage by looking up the correspondingtemperature in a stored conversion table, or by calculating thetemperature using a fourth order polynomial. The heater controlsubroutine 480 gradually controls a ramp up/down of current applied tothe heat module. The gradual ramp up/down increases the life andreliability of the heat module. Additionally, a built-in-fail-safe modecan be included to detect process safety compliance, and can shut downoperation of the heat module if the processing chamber 10 is notproperly set up.

[0048] The plasma control subroutine 490 comprises program code forsetting the RF bias voltage power level applied to the processelectrodes in the processing chamber 10, and optionally, to set thelevel of the magnetic field generated in the reactor. Similar to thepreviously described chamber component subroutines, the plasma controlsubroutine 490 is invoked by the chamber manager subroutine 440.

[0049] The pretreatment and method for forming a pretreated layer of thepresent invention is not limited to any specific apparatus or to anyspecific plasma excitation method. The above CVD system description ismainly for illustrative purposes, and other CVD equipment such aselectrode cyclotron resonance (ECR) plasma CVD devices,induction-coupled RF high density plasma CVD devices, or the like may beemployed. Additionally, variations of the above described system such asvariations in susceptor design, heater design, location of RF powerconnections and others are possible. For example, the substrate could besupported and heated by a resistively heated susceptor.

[0050] Deposition Of A Low Dielectric Constant Film

[0051]FIG. 3 shows a damascene structure having a low dielectricconstant film of the present invention deposited thereon. The lowdielectric constant film is deposited as a dielectric layer 314 on adielectric liner or barrier layer 312. A cap layer 316 is deposited onthe dielectric layer 314. The cap layer 316 acts as an etch stop duringfurther substrate processing or alternatively, as a liner layer. The caplayer 316, dielectric layer 314, and dielectric liner or barrier layer312 are pattern etched to define the openings of interconnects 317 suchas lines that expose underlying conducive features 310. A conductiveliner/barrier layer 318 is deposited within the interconnects 317, and aconductive material 320 is deposited thereon to fill the interconnects317. The substrate is typically planarized, as shown, after deposition.

[0052] FIGS. 4A-4C are cross sectional views of a substrate 300 havingthe steps of the invention formed thereon. As shown in FIG. 4A, adielectric layer 314 of the low dielectric constant film is deposited onthe liner or barrier layer 312 to a thickness between about 5,000 Å toabout 10,000 Å, depending on the size of the structure to be fabricated.The liner or barrier layer 312 may be a silicon carbide layer, forexample, from the PECVD of an alkylsilane compound using a plasma of aninert gas. The silicon carbide layer may be doped with oxygen ornitrogen. The liner/barrier layer 312 may alternatively comprise anothermaterial, such as silicon nitride, which minimizes oxidation and/ordiffusion of conductive materials, such as copper, which may compriseconductive features 310 previously formed in the substrate 300.

[0053] The cap layer 316, which can be a silicon carbide layer have alow dielectric constant, is then deposited on the dielectric layer 314by reaction of the trimethylsilane to a thickness of about 200 Å toabout 1000 Å using RF power in the range between about 10 and about 1000wafts for a 200 mm substrate. The silicon carbide material may be dopedwith oxygen or nitrogen.

[0054] As shown in FIG. 4B, the cap layer 316, the dielectric layer 314,and the liner or barrier layer 312 are then pattern etched to define theinterconnects 317 and to expose the conductive feature 310 in substrate300. Preferably, the cap layer 316, the dielectric layer 314, and theliner or barrier layer 312 are pattern etched using conventionalphotolithography and etch processes for silicon carbide films. Any photoresist or other material used to pattern the cap layer 316 is removedusing an oxygen strip or other suitable process.

[0055] Following etching of the deposited material and removal of photoresist materials, exposed portions of the cap layer 316, the dielectriclayer 314, and the liner or barrier layer 312 may be treated with areactive pre-clean process to remove contaminants, particulate matter,residues, and oxides that may have formed on the exposed portions of theinterconnects 317 and on the surface of the substrate. The reactivepre-clean process comprises exposing the substrate to a plasma,preferably comprising hydrogen, argon, helium, nitrogen, or mixturesthereof, at a power density between of 0.03 watts/cm² and about 3.2watts/cm², or at a power level between about 10 watts and 1000 for a 200millimeter substrate. The processing chamber is maintained at a pressureof about 20 Torr or less and at a substrate temperature of about 450° C.or less during the reactive clean process.

[0056] Referring to FIG. 4C, after the cap layer 316, the dielectriclayer 314, and the liner or barrier layer 312 have been etched to definethe interconnects 317 and the photo resist has been removed, theinterconnects 317 are filled with a conductive material 320. Thestructure is preferably formed with a conductive material such asaluminum, copper, tungsten, or combinations thereof. Presently, thetrend is to use copper to form the smaller features due to the lowresistivity of copper (1.7 Ω-cm compared to 3.1 Ω-cm for aluminum).

[0057] Preferably, the conductive barrier layer 318 is first depositedconformably in the interconnects 317 to prevent copper migration intothe surrounding silicon and/or dielectric material. Barrier layersinclude titanium, titanium nitride, tantalum, tantalum nitride, andcombinations thereof among other conventional barrier layer materials.Thereafter, copper 320 is deposited using chemical vapor deposition,physical vapor deposition, electroplating, or combinations thereof, toform the conductive structure. Once the structure has been filled withcopper or other conductive material, the surface is planarized usingchemical mechanical polishing to produce the finished damascenestructure shown in FIG. 3.

[0058]FIG. 5 shows dual damascene structure which includes two lowdielectric constant films and two silicon carbide cap layers or dopedsilicon carbide cap layers deposited thereon. A conductive feature 502is formed in a substrate 500. The first low dielectric constant film isdeposited as a first dielectric layer 510 on a liner or barrier layer512, for example, silicon carbide. A first silicon carbide cap layer 514is deposited on the first dielectric layer 510. The silicon carbide caplayer 514 reduces the dielectric constant of the low dielectric constantfilm and is pattern etched to define the openings of verticalinterconnects such as contacts/vias. For the dual damascene application,a second dielectric layer 518 comprising the second low dielectricconstant film is deposited over the patterned silicon carbide cap layer514. The second silicon carbide cap layer 519 is deposited on the seconddielectric layer 518 and pattern etched to define horizontalinterconnects such as lines. An etch process is performed to define thehorizontal interconnects down to the first silicon carbide layer 314which functions as an etch stop, and to define the verticalinterconnects and expose the conductive feature 502 in substrate 500prior to filling the interconnects with a conductive material 526.

[0059] A preferred method for making the dual damascene structure shownin FIG. 5 is sequentially depicted in FIGS. 6A-6E, which are crosssectional views of a substrate having the steps of the invention formedthereon. As shown in FIG. 6A, an initial first dielectric layer 510 ofthe low dielectric constant film is deposited on the liner or barrierlayer 512 to a thickness between about 5,000 Å and about 10,000 Å,depending on the size of the structure to be fabricated. The liner layer512 may be a silicon carbide layer, which may be doped with oxygen ornitrogen. The liner/barrier layer 512 may alternatively comprise anothermaterial, such as silicon nitride, which minimizes oxidation and/ordiffusion of conductive materials, such as copper, which may compriseconductive features 502 previously formed in the substrate 500.

[0060] As shown in FIG. 6B, the first cap layer 514, which includes asilicon carbide layer or doped silicon carbide layer is then depositedon the first dielectric layer to a thickness between about 200 and about1000 Å using RF power in the range between about 10 and about 1000 wattsfor a 200 mm substrate. The first cap layer 514 is then pattern etchedto define the contact/via openings 516 and to expose first dielectriclayer 510 in the areas where the contacts/vias are to be formed as shownin FIG. 6C. Preferably, the first cap layer 514 is pattern etched usingconventional photolithography and etch processes for silicon carbidefilms.

[0061] After the first cap layer 514 has been etched to pattern thecontacts/vias 516 and the photo resist has been removed, a seconddielectric layer 518 is deposited over the first cap layer 514 to athickness between about 5,000 Å and about 10,000 Å as described for thefirst dielectric layer 510 as shown in FIG. 6D.

[0062] A second cap layer 519, which includes a silicon carbide layer ordoped silicon carbide layer is then deposited on the second dielectriclayer 518 to a thickness of about 200 to about 1000 Å. The siliconcarbide material may be doped with oxygen or nitrogen. The second caplayer 519 is then patterned to define lines 520, as shown in FIG. 6E.The lines 520 and contacts/vias 516 are then etched using reactive ionetching or other anisotropic etching techniques to define themetallization structure (i.e., the openings for the lines andcontact/via) and expose the conductive feature 502 as shown in FIG. 6F.Any photo resist or other material used to pattern and etch the secondcap layer 519 is removed using an oxygen strip or other suitableprocess.

[0063] Following etching of the deposited material and removal of photoresist materials, exposed portions of the second cap layer 519, thesecond dielectric layer 518, the first cap layer 514, the firstdielectric layer 510, and the liner or barrier layer 512 may be treatedwith a reactive pre-clean process, as described above, to removecontaminants, particulate matter, residues, and oxides that may haveformed on the exposed portions of the contact/via openings 516, the lineopenings 520, and the conductive feature 502.

[0064] The metallization structure is then formed with a conductivematerial such as aluminum, copper, tungsten or combinations thereof.Presently, the trend is to use copper to form the smaller features dueto the low resistivity of copper (1.7 Ω-cm compared to 5.1 Ω-cm foraluminum). Preferably, as shown in FIG. 6G, a conductive barrier layer524 is first deposited conformably in the metallization pattern toprevent copper migration into the surrounding silicon and/or dielectricmaterial. Barrier layers include titanium, titanium nitride, tantalum,tantalum nitride, and combinations thereof among other conventionalbarrier layer materials. Thereafter, copper 526 is deposited usingeither chemical vapor deposition, physical vapor deposition,electroplating, or combinations thereof to form the conductivestructure. Once the structure has been filled with copper or othermetal, the surface is planarized using chemical mechanical polishing asshown in FIG. 5.

[0065] These processing steps are preferably integrated on a processingplatform to avoid interim contamination of the substrate. One exemplaryintegrated processing tool is an ENDURA platform available from AppliedMaterials, Inc. of Santa Clara, Calif. FIG. 7 shows a schematic planview of an exemplary multi-chamber processing system 700, such as theENDURA platform. A similar multi-chamber processing system is disclosedin U.S. Pat. No. 5,186,718, entitled “Stage Vacuum Wafer ProcessingSystem and Method,” issued on Feb. 16, 1993, which is incorporated byreference herein.

[0066] The system 700 generally includes load lock chambers 702, 704 forthe transfer of substrates into and out from the system 700. Since thesystem 700 is typically under vacuum, the load lock chambers 702, 704may “pump down” the substrates introduced into the system 700. A firstrobot 710 may transfer the substrates between the load lock chambers702, 704, and a first set of one or more substrate processing chambers712, 714, 716, 718 (four are shown). Each processing chamber 712, 714,716, 718, can be outfitted to perform a number of substrate processingoperations such as cyclical layer deposition, chemical vapor deposition(CVD), physical vapor deposition (PVD), etch, pre-clean, degas,orientation and other substrate processes. The first robot 710 alsotransfers substrates to and from one or more transfer chambers 722, 724.

[0067] The transfer chambers 722, 724, are used to maintain ultrahighvacuum conditions while allowing substrates to be transferred within thesystem 700. A second robot 730 may transfer the substrates between thetransfer chambers 722, 724 and a second set of one or more processingchambers 732, 734, 736, 738. Similar to processing chambers 712, 714,716, 718, the processing chambers 732, 734, 736, 738 can be outfitted toperform a variety of substrate processing operations, such as cyclicaldeposition, chemical vapor deposition (CVD), physical vapor deposition(PVD), etch, pre-clean, degas, and orientation, for example. Any of thesubstrate processing chambers 712, 714, 716, 718, 732, 734, 736, 738 maybe removed from the system 700 if not necessary for a particular processto be performed by the system 700.

[0068] In one arrangement, each processing chamber 732 and 738 may be acyclical deposition chamber adapted to deposit a nucleation layer; eachprocessing chamber 734 and 736 may be a cyclical deposition chamber, achemical vapor deposition chamber, or a physical vapor depositionchamber adapted to form a bulk fill deposition layer; each processingchamber 712 and 714 may be a chemical vapor deposition chamber, or acyclical deposition chamber adapted to deposit a dielectric layer asdescribed herein; and each processing chamber 716 and 718 may be an etchchamber outfitted to etch apertures or openings for interconnectfeatures. This one particular arrangement of the system 700 is providedto illustrate the invention and should not be used to limit the scope ofthe invention.

[0069] The following examples illustrate the low dielectric films of thepresent invention. The films were deposited on 200 mm substrates using achemical vapor deposition chamber, such as the “Producer DxZ” system,available from Applied Materials, Inc. of Santa Clara, Calif.

EXAMPLE 1

[0070] A low dielectric constant film was deposited on each of three 200mm substrates at about 8 Torr and temperature of about 200° C. Thefollowing processing gases and flow rates were used:

[0071] Alpha-terpinene (ATP), at 3,000 mgm;

[0072] Diethoxymethylsilane (DEMS), at 800 mgm; and

[0073] Carbon dioxide, at 1,000 sccm.

[0074] Each substrate was positioned 300 mils from the gas distributionshowerhead. A power level of 600 W at a frequency of 13.56 MHz wasapplied to the showerhead for plasma enhanced deposition of the films.Each film was deposited at a rate of about 2,700 A/min, and had adielectric constant (k) of about 5.4 measured using SSM 5100 Hg CVmeasurement tool at 0.1 MHz. Each film also exhibited a hardness ofabout 0.1 GPa.

[0075] Thermal Anneal:

[0076] The first deposited film was subjected to a thermal annealprocess. The anneal treatment utilized a temperature of about 425° C. ata pressure of about 10 Torr in an inert gas environment for about 4hours. Shorter anneal times resulted in higher k values. The thermallyannealed film had a lowest k value of about 2.1 and a hardness of about0.2 GPa.

[0077] E-BEAM (˜400° C.:

[0078] The second deposited film was subjected to a high temperatureelectron beam (e-beam) treatment using a dose of about 300 μc/cm², atabout 4.5 KeV and 1.5 mA, and at about 400° C. The e-beam treatmentlasted for about 2 minutes. Following the e-beam treatment, the filmexhibited a dielectric constant of about 2.1 which is about 60% lessthan the non-cured films and similar to the lowest value of thethermally annealed film. The e-beam film also exhibited a hardness ofabout 0.7 GPa, which is about an 600% increase compared to the non-curedfilms, and a 250% increase compared to the thermally annealed film.

[0079] E-Beam at Room Temperature:

[0080] The third deposited film was subjected to a low temperatureelectron beam (e-beam) treatment using a dose of about 300 μc/cm², atabout 4.5 KeV and 1.5 mA, and at about 35° C. The e-beam treatmentlasted for about 2 minutes. Following the e-beam treatment, the filmexhibited a dielectric constant of about 2.3 which is about 57% lessthan the non-cured films. The e-beam film also exhibited a hardness ofabout 0.5 GPa, which is about an 400% increase compared to the non-curedfilms, and a 150% increase compared to the thermally annealed film.

EXAMPLE 2

[0081] A low dielectric constant film was deposited on each of threesubstrates at about 8 Torr and temperature of about 225° C. Thefollowing processing gases and flow rates were used:

[0082] Alpha-terpinene (ATP), at 3,000 mgm;

[0083] Diethoxymethylsilane (DEMS), at 800 mgm;

[0084] Carbon dioxide, at 1,500 sccm; and

[0085] Oxygen, at 100 sccm.

[0086] Each substrate was positioned 300 mils from the gas distributionshowerhead. A power level of 600 W at a frequency of 13.56 MHz wasapplied to the showerhead for plasma enhanced deposition of the films.Each film was deposited at a rate of about 1,800 A/min, and had adielectric constant (k) of about 2.85 measured using SSM 5100 Hg CVmeasurement tool at 0.1 MHz. Each film also exhibited a hardness ofabout 0.23 GPa.

[0087] Thermal Anneal

[0088] The first deposited film was subjected to a thermal annealprocess. The anneal treatment utilized a temperature of about 450° C. ata pressure of about 10 Torr in an inert gas environment for about 30minutes. Shorter anneal times resulted in higher k values. The thermallyannealed film had a refractory index (R1) of about 1.29, a lowest kvalue of about 2.08, and a hardness of about 0.23 GPa.

[0089] E-BEAM@400° C. and 200 μc/cm²:

[0090] The second deposited film was subjected to a high temperatureelectron beam (e-beam) treatment using a dose of about 200 μc/cm², atabout 4.5 KeV and 1.5 mA, and at about 400° C. The e-beam treatmentlasted for about 100 seconds. Following the e-beam treatment, the filmexhibited a dielectric constant of about 2.07 which is about 27% lessthan the non-cured films and similar to the lowest value of thethermally annealed film. The e-beam film also exhibited a hardness ofabout 0.42 GPa, which is about an 80% increase compared to the non-curedfilms and the thermally annealed film.

[0091] E-BEAM@400° C. and 500 μc/cm²:

[0092] The third deposited film was subjected to a low temperatureelectron beam (e-beam) treatment using a dose of about 500 μc/cm², atabout 4.5 KeV and 1.5 mA, and at about 35° C. The e-beam treatmentlasted for about 250 seconds. Following the e-beam treatment, the filmexhibited a dielectric constant of about 2.14 which is about 25% lessthan the non-cured films. The e-beam film also exhibited a hardness ofabout 0.74 GPa, which is about a 220% increase compared to the non-curedfilms and the thermally annealed film.

EXAMPLE 3

[0093] A low dielectric constant film was deposited on each of twosubstrates at about 8 Torr and a temperature of about 225° C. Thefollowing processing gases and flow rates were used:

[0094] Alpha-terpinene (ATP), at 4,000 mgm;

[0095] Octamethylcyclotetrasiloxane (OMCTS), at 200 mgm;

[0096] Oxygen, at 200 sccm; and

[0097] Carbon dioxide 2,000 sccm.

[0098] Each substrate was positioned about 300 mils from the gasdistribution showerhead. A power level of 500 W at a frequency of 13.56MHz was applied o the showerhead for plasma enhanced deposition of thefilms. Each film was deposited at a rate of about 1,000 A/min, and had adielectric constant (k) of about 4.0 measured using SSM 5100 Hg CVmeasurement tool at 0.1 MHz. Each film also exhibited a hardness ofabout 0.1 GPa.

[0099] E-BEAM@400° C. and 120 micro c/cm²:

[0100] The first deposited film was subjected to a high temperatureelectron beam (e-beam) treatment using a dose of about 120 micro c/cm²,at about 4.5 KeV and 1.5 mA, and at about 400° C. The e-beam treatmentlasted for about 30 seconds. Following the e-beam treatment, the filmexhibited a dielectric constant of about 1.9 which is about 52% lessthan the non-cured films. The e-beam film also exhibited a hardness ofabout 0.5 GPa, which is about a 400% increase compared to the non-curedfilms.

[0101] E-BEAM@400° C. and 600 micro c/cm²:

[0102] The second deposited film was subjected to a low temperatureelectron beam (e-beam) treatment using a dose of about 600 micro c/cm2,at about 4.5 KeV and 1.5 mA, and at about 400° C. The e-beam treatmentlasted for about 150 seconds. Following the e-beam treatment, the filmexhibited a dielectric constant of about 2.2, which is about 45% lessthan the non-cured films. The e-beam film also exhibited a hardness ofabout 0.8 GPa, which is about a 700% increase compared to the non-curedfilms.

EXAMPLE 4

[0103] A low dielectric constant film was deposited on a substrate atabout 8 Torr and a temperature of about 225° C. The following processinggases and flow rates were used:

[0104] ATP, at 3,000 mgm;

[0105] TMS, at 500 sccm;

[0106] DEMS, at 600 mgm;

[0107] Oxygen, at 100 sccm; and

[0108] Carbon dioxide, at 1,500 sccm.

[0109] The substrate was positioned about 300 mils from the gasdistribution showerhead. A power level of 600 W at a frequency of 13.56MHz was applied o the showerhead for plasma enhanced deposition of thefilms. The film was deposited at a rate of about 2,000 A/min, and had adielectric constant (k) of about 4.3 measured using SSM 5100 Hg CVmeasurement tool at 0.1 MHz. The film also exhibited a hardness of about0.1 GPa.

[0110] E-BEAM@400° C. and 200 micro c/cm²:

[0111] The deposited film was subjected to a high temperature electronbeam (e-beam) treatment using a dose of about 200 micro c/cm2, at about4.5 KeV and 1.5 mA, and at about 400° C. The e-beam treatment lasted forabout 30 seconds. Following the e-beam treatment, the film exhibited adielectric constant of about 2.2 which is about 50% less than thenon-cured film. The e-beam film also exhibited a hardness of about 0.7GPa, which is about a 600% increase compared to the non-cured film.

EXAMPLE 5:

[0112] A low dielectric constant film was deposited on a substrate atabout 8 Torr and a temperature of about 225° C. The following processinggases and flow rates were used:

[0113] ATP, at 4,000 mgm;

[0114] TMS, at 1,000 sccm;

[0115] OMCTS, at 200 mgm

[0116] Oxygen, at 100 sccm; and

[0117] Carbon dioxide, at 1,500 sccm.

[0118] The substrate was positioned about 300 mils from the gasdistribution showerhead. A power level of 500 W at a frequency of 13.56MHz was applied o the showerhead for plasma enhanced deposition of thefilms. The film was deposited at a rate of about 1,600 A/min, and had adielectric constant (k) of about 4.5 measured using SSM 5100 Hg CVmeasurement tool at 0.1 MHz. The film also exhibited a hardness of about0.1 GPa.

[0119] E-BEAM@400° C. and 200 micro c/cm²:

[0120] The deposited film was subjected to a high temperature electronbeam (e-beam) treatment using a dose of about 200 micro c/cm2, at about4.5 KeV and 1.5 mA, and at about 400° C. The e-beam treatment lasted forabout 30 seconds. Following the e-beam treatment, the film exhibited adielectric constant of about 2.3 which is about 50% less than thenon-cured film. The e-beam film also exhibited a hardness of about 0.7GPa, which is about a 600% increase compared to the non-cured film.

[0121] While the foregoing is directed to embodiments of the presentinvention, other and further embodiments of the invention may be devisedwithout departing from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A method for depositing a low dielectric constant film, comprising:delivering a gas mixture comprising one or more organosilicon compoundsand one or more hydrocarbon compounds having at least one cyclic groupto a substrate surface at deposition conditions sufficient to deposit anon-cured film comprising the at least one cyclic group on the substratesurface and having a hardness less than about 0.3 GPa; and substantiallyremoving the at least one cyclic group from the non-cured film using anelectron beam at curing conditions sufficient to provide a dielectricconstant less than 2.5 and a hardness greater than 0.5 GPa.
 2. Themethod of claim 1, wherein the one or more organosilicon compounds hasan oxygen to silicon ratio of at least 1:1.
 3. The method of claim 1,wherein the one or more organosilicon compounds has an oxygen to siliconratio of at least 2:1.
 4. The method of claim 1, wherein the one or moreorganosilicon compounds has an oxygen to silicon ratio of about 4:1. 5.The method of claim 1, wherein the one or more organosilicon compoundsis selected from the group consisting of3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane(TMCTS), octamethylcyclotetrasiloxane (OMCTS),1,3,5,7,9-pentamethylcyclopentasiloxane,1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene,hexamethylcyclotrisiloxane, diethoxymethylsilane (DEMS), dimethyl,dimethoxysilane (DMDMOS), dimethoxymethylvinylsilane (DMMVS),trimethylsilane (TMS), derivatives thereof, and mixtures thereof.
 6. Themethod of claim 1, wherein the at least one cyclic group is a partiallysaturated ring of five or six carbon atoms.
 7. The method of claim 1,wherein the at least one cyclic groups is an unsaturated ring of five orsix carbon atoms.
 8. The method of claim 1, wherein the at least onecyclic groups is a saturated ring of five or six carbon atoms.
 9. Themethod of claim 1, wherein the at least one cyclic group comprises astructure selected from a group consisting of aromatics, aryls, phenyls,cyclohexanes, cyclohexadienes, cycloheptadienes, and combinationsthereof.
 10. The method of claim 1, wherein the one or more compoundshaving at least one cyclic group is selected from the group consistingof alpha-terpinene (ATP), vinylcyclohexane (VCH), norbornadiene,phenylacetate, and combinations thereof.
 11. The method of claim 1,wherein the gas mixture further comprises an oxidizing gas.
 12. Themethod of claim 11, wherein the oxidizing gas comprises oxygen, carbondioxide, or 2,3-butanedione.
 13. The method of claim 11, wherein theoxidizing gas comprises a mixture of two or more oxidants selected froma group consisting of ozone, oxygen, carbon dioxide, carbon monoxide,water and nitrous oxide.
 14. The method of claim 1, wherein thedeposition conditions comprise a power density ranging from about 0.03W/cm² to about 3.2 W/cm².
 15. The method of claim 1, wherein thedeposition conditions comprise a substrate temperature of about 100° C.to about 400° C. and a pressure from about 4 Torr to about 10 Torr. 16.The method of claim 1, wherein the curing conditions comprise anelectron beam dosage from about 200 to about 400 micro coulombs per cm².17. The method of claim 14, wherein the curing conditions comprise atemperature greater than room temperature.
 18. A method for depositing alow dielectric constant film, comprising: delivering a gas mixturecomprising one or more organosilicon compounds, one or more hydrocarboncompounds having at least one cyclic group, and two or more oxidizinggases to a substrate surface at deposition conditions sufficient todeposit a non-cured film comprising the at least one cyclic group on thesubstrate surface and having a hardness less than 0.3 GPa; andsubstantially removing the at least one cyclic group from the non-curedfilm using an electron beam at curing conditions sufficient to provide adielectric constant less than 2.2 and a hardness greater than 0.4 GPa.19. The method of claim 18, wherein the one or more compounds having atleast one cyclic group is selected from the group consisting ofalpha-terpinene (ATP), vinylcyclohexane (VCH), norbornadiene,phenylacetate, and combinations thereof.
 20. The method of claim 18,wherein the one or more organosilicon compounds is selected from thegroup consisting of 3,5-trisilano-2,4,6-trimethylene,1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS),octamethylcyclotetrasiloxane (OMCTS),1,3,5,7,9-pentamethylcyclopentasiloxane,1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene,hexamethylcyclotrisiloxane, diethoxymethylsilane (DEMS), dimethyl,dimethoxysilane (DMDMOS), dimethoxymethylvinylsilane (DMMVS),trimethylsilane (TMS), derivatives thereof, and mixtures thereof. 21.The method of claim 18, wherein the one or more the oxidizing gascomprises oxygen, carbon dioxide, or 2,3-butanedione, ozone, carbonmonoxide, water and nitrous oxide.
 22. A method for depositing a lowdielectric constant film, comprising: delivering a gas mixturecomprising two or more organosilicon compounds, one or more hydrocarboncompounds having at least one cyclic group, and one or more oxidizinggases to a substrate surface at deposition conditions sufficient todeposit a non-cured film comprising the at least one cyclic group on thesubstrate surface; and substantially removing the at least one cyclicgroup from the non-cured film using an electron beam at curingconditions sufficient to provide a dielectric constant less than 2.5 anda hardness greater than 0.5 GPa, wherein the electron beam has a dosagegreater than about 200 micro coulombs per cm².
 23. The method of claim22, wherein the one or more compounds having at least one cyclic groupis selected from the group consisting of alpha-terpinene (ATP),vinylcyclohexane (VCH), norbornadiene, phenylacetate, and combinationsthereof.
 24. The method of claim 22, wherein the two or moreorganosilicon compounds is selected from the group consisting of3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane(TMCTS), octamethylcyclotetrasiloxane (OMCTS),1,3,5,7,9-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, hexamethylcyclotrisiloxane, diethoxymethylsilane(DEMS), dimethyl, dimethoxysilane (DMDMOS), dimethoxymethylvinylsilane(DMMVS), trimethylsilane (TMS), derivatives thereof, and mixturesthereof.
 25. The method of claim 22, wherein the one or more theoxidizing gas comprises oxygen, carbon dioxide, or 2,3-butanedione,ozone, carbon monoxide, water and nitrous oxide.
 26. The method of claim22, wherein the two or more organosilicon compounds comprises a mixtureof at least one linear organosilicon compound and at least one cyclicorganosilicon compound.